﻿/*
 * [The "BSD licence"]
 * Copyright (c) 2011 Terence Parr
 * All rights reserved.
 *
 * Conversion to C#:
 * Copyright (c) 2011 Sam Harwell, Tunnel Vision Laboratories, LLC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

namespace Antlr4.StringTemplate.Compiler
{
    using Antlr.Runtime;

    /** Represents the name of a formal argument defined in a template:
     *
     *  test(a,b,x=defaultvalue) ::= "&lt;a&gt; &lt;n&gt; &lt;x&gt;"
     *
     *  Each template has a set of these formal arguments or uses
     *  a placeholder object: UNKNOWN (indicating that no arguments
     *  were specified such as when we create a template with "new Template(...)").
     *
     *  Note: originally, I tracked cardinality as well as the name of an
     *  attribute.  I'm leaving the code here as I suspect something may come
     *  of it later.  Currently, though, cardinality is not used.
     */
    public class FormalArgument
    {
        /*
            // the following represent bit positions emulating a cardinality bitset.
            public static final int OPTIONAL = 1;     // a?
            public static final int REQUIRED = 2;     // a
            public static final int ZERO_OR_MORE = 4; // a*
            public static final int ONE_OR_MORE = 8;  // a+
            public static final String[] suffixes = {
                null,
                "?",
                "",
                null,
                "*",
                null,
                null,
                null,
                "+"
            };
            protected int cardinality = REQUIRED;
             */

        private readonly string name;

        private int index; // which argument is it? from 0..n-1

        /** If they specified default value x=y, store the token here */
        private readonly IToken defaultValueToken;
        private object defaultValue; // x="str", x=true, x=false
        private CompiledTemplate compiledDefaultValue; // x={...}

        public FormalArgument(string name)
        {
            this.name = name;
        }

        public FormalArgument(string name, IToken defaultValueToken)
        {
            this.name = name;
            this.defaultValueToken = defaultValueToken;
        }

        public string Name
        {
            get
            {
                return name;
            }
        }

        public int Index
        {
            get
            {
                return index;
            }

            internal set
            {
                index = value;
            }
        }

        public IToken DefaultValueToken
        {
            get
            {
                return defaultValueToken;
            }
        }

        public object DefaultValue
        {
            get
            {
                return defaultValue;
            }

            set
            {
                defaultValue = value;
            }
        }

        public CompiledTemplate CompiledDefaultValue
        {
            get
            {
                return compiledDefaultValue;
            }

            internal set
            {
                compiledDefaultValue = value;
            }
        }

        /*
        public static String getCardinalityName(int cardinality) {
            switch (cardinality) {
                case OPTIONAL : return "optional";
                case REQUIRED : return "exactly one";
                case ZERO_OR_MORE : return "zero-or-more";
                case ONE_OR_MORE : return "one-or-more";
                default : return "unknown";
            }
        }
        */

        public override bool Equals(object o)
        {
            if (o == null || !(o is FormalArgument))
            {
                return false;
            }

            FormalArgument other = (FormalArgument)o;
            if (!this.name.Equals(other.name))
            {
                return false;
            }

            // only check if there is a default value; that's all
            return !((this.defaultValueToken != null && other.defaultValueToken == null) ||
                   (this.defaultValueToken == null && other.defaultValueToken != null));
        }

        public override int GetHashCode()
        {
            return name.GetHashCode() + defaultValueToken.GetHashCode();
        }

        public override string ToString()
        {
            if (defaultValueToken != null)
                return name + "=" + defaultValueToken.Text;

            return name;
        }
    }
}
